We ae studying the chemical, rheological and mucociliary transport properties of mucus obtained from beagles equipped with tracheal pouches. The chemical properties of purified mucin and of reduced mucin fractions are being characterized, and their physicochemical properties determined. The effect of alterations in mucin chemistry on ciliary transport is elucidated via the frog palate transport model. The effect on mucus secretion and the resulting mucus properties of cholinergic and anticholinergic agents administered to the dogs is being followed by several methods. The results of these studies should lead to a better understanding of the physicochemistry of mucus flow and its important role in obstructive lung disease.